oscillating (part of speech: verb)
vibrating, tottering, oscillating, bobbing, beating, teeter-tottering, undulating, pulsating, swaying, alternating, seesawing, pulsing, rocking, back-and-forth, wobbling, trembling, staggering, wagging, radiating, throbbing, teeter-totter, ticking, zigzag
doubting (part of speech: verb)
procrastinating (part of speech: verb)
changing (part of speech: verb)
irresolute (part of speech: adjective)
inconsistent, dillydallying, double-minded, ambivalent, erratic, irresponsible, hesitant, tentative, halfhearted, impulsive, spineless, infirm, shrinking, shifty, uncertain, flitting, weak, shy, watery, undecided, insipid, unwilling, shilly-shally, unsure, fly-by-night, unresolved, indecisive, capricious, yellow, undependable
changeable (part of speech: adjective)
restless, transposable, adaptable, unreliable, protean, vicissitudinous, irresolute, fluid, changeable, modifiable, shifting, mercurial, mutable, precarious, varying, unsteady, movable, fickle, wavering, volatile, inconstant, adjustable, versatile, alterable, convertible, changeful, variable, reformable, unstable, flighty, flexible, transformable, ever-changing, unsettled
capricious (part of speech: adjective)
- He is not intellectual- he is the most vacillating, most meek and timid of mortals- but he is a gentleman in his own poor fashion, and has a sort of fluttering chivalry about him, which, though feeble, is better than none. - "Thelma", Marie Corelli.
- Well, I'm in charge of a strip of frontier territory, but so far I've had the veto of a cautious and vacillating superior to contend with. - "Blake's Burden", Harold Bindloss.
- It was this, again, which made him so uncertain and vacillating as to how he should use those successes when they came; which made him suggest now this, now that basis for peace after each victory, but never to insist very particularly, however surprising and thorough his work in the field, upon the French throne. - "Crecy", Hilaire Belloc.